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Related papers: Radiative Transfer in 3D

200 papers

Emission features formed through Raman scattering with atomic hydrogen provide unique and crucial information to probe the distribution and kinematics of a thick neutral region illuminated by a strong far UV emission source. We introduce a…

Solar and Stellar Astrophysics · Physics 2021-01-13 Seok-Jun Chang , Hee-Won Lee

We present a new code for solving the molecular and atomic excitation and radiation transfer problem in a molecular gas and predicting emergent spectra. This code works in arbitrary three dimensional geometry using unstructured Delaunay…

Solar and Stellar Astrophysics · Physics 2015-05-19 C. Brinch , M. R. Hogerheijde

We describe an approach for incorporating radiative transfer into 3D hydrodynamic cosmological simulations. The method, while approximate, allows for a self-consistent treatment of self-shielding and shadowing, diffuse and point sources of…

Astrophysics · Physics 2007-05-23 Michael L. Norman , Paschalis Paschos , Tom Abel

The Atacama Large Millimeter/submillimeter Array (ALMA) will be a valuable tool for observing the chromosphere of our Sun at (sub-)millimeter wavelengths at high spatial, temporal and spectral resolution and as such has great potential to…

Solar and Stellar Astrophysics · Physics 2015-02-24 Sven Wedemeyer , Tim Bastian , Roman Brajsa , Miroslav Barta , Masumi Shimojo

The current generation of radio and millimeter telescopes, particularly the Atacama Large Millimeter Array (ALMA), offers enormous advances in observing capabilities. While these advances represent an unprecedented opportunity to facilitate…

Instrumentation and Methods for Astrophysics · Physics 2019-04-26 Paul Rosen , Anil Seth , Betsy Mills , Adam Ginsburg , Julia Kamenetzky , Jeff Kern , Chris R. Johnson , Bei Wang

Since the mass of the electron is very small relative to atomic masses, Thomson scattering of low-energy photons ($h\nu \ll m_ec^2$) produces thermal Doppler frequency shifts that are much larger than atomic Doppler widths. A method is…

Astrophysics · Physics 2011-05-23 G. B. Rybicki , D. G. Hummer

Context: Knowledge about hot, massive stars is usually inferred from quantitative spectroscopy. To analyse non-spherical phenomena, the existing 1D codes must be extended to higher dimensions, and corresponding tools need to be developed.…

Solar and Stellar Astrophysics · Physics 2019-12-25 L. Hennicker , J. Puls , N. D. Kee , J. O. Sundqvist

Accurate angular quadratures are crucial for the numerical solution of three-dimensional (3D) radiative transfer problems, especially when the spectral line polarisation produced by the scattering of anisotropic radiation is included. There…

Solar and Stellar Astrophysics · Physics 2021-01-27 Jaume Jaume Bestard , Jiří Štěpán , Javier Trujillo Bueno

Considering the relatively high precision that will be reached by future observatories, it has recently become clear that one dimensional (1D) atmospheric models, in which the atmospheric temperature and composition of a planet are…

Earth and Planetary Astrophysics · Physics 2022-02-02 Aurélien Falco , Tiziano Zingales , William Pluriel , Jérémy Leconte

Using a multi-plane lensing method that we have developed, we follow the evolution of light beams as they propagate through inhomogeneous universes. We use a P3M code to simulate the formation and evolution of large-scale structure. The…

Astrophysics · Physics 2016-01-27 Premana W. Premadi , Hugo Martel , Richard A. Matzner

Direct measurements of cosmic ray (CR) species combined with observations of their associated gamma-ray emissions can be used to constrain models of CR propagation, trace the structure of the Galaxy, and search for signatures of new…

High Energy Astrophysical Phenomena · Physics 2018-04-11 Gudlaugur Johannesson , Troy A. Porter , Igor V. Moskalenko

Observations of the Sun at millimeter and submillimeter wavelengths offer a unique probe into the structure, dynamics, and heating of the chromosphere; the structure of sunspots; the formation and eruption of prominences and filaments; and…

Higher resolution telescopes as well as 3D numerical simulations will require the development of detailed 3D radiative transfer calculations. Building upon our previous work we extend our method to include both continuum and line transfer.…

Astrophysics · Physics 2009-11-13 E. Baron , Peter H. Hauschildt

We show the necessity for a new approach towards comprehensive and consistent simulations of the propagation of galactic cosmic rays. Our developments are optimised for addressing the spatially 3-dimensional inhomogeneous diffusion problem…

Instrumentation and Methods for Astrophysics · Physics 2013-08-14 M. Werner , R. Kissmann , A. W. Strong , O. Reimer

Owing to their intricate variable density architecture, and as a principal site of star formation, molecular clouds represent one of the most functionally significant, yet least understood features of our universe. To unravel the intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2021-09-08 Nia Imara , John C. Forbes , James C. Weaver

Dark matter (DM) clustering at the present epoch is investigated from a fractal viewpoint in order to determine the scale where the self-similar scaling property of the DM halo distribution transits to homogeneity. Methods based on…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-29 David Kraljic

Astronomers have used observations of the Galactic gas and dust via infrared, microwave, and radio to study molecular clouds in extreme environments such as the Galactic center. More recently, X- ray telescopes have opened up a new…

Riemannian diffusion models draw inspiration from standard Euclidean space diffusion models to learn distributions on general manifolds. Unfortunately, the additional geometric complexity renders the diffusion transition term inexpressible…

Machine Learning · Computer Science 2023-11-01 Aaron Lou , Minkai Xu , Stefano Ermon

We use the Atacama Large sub/Millimetre Array (ALMA) to efficiently observe spectral lines across Bands 3, 4, 5, 6, 7, and 8 at high-resolution (0.5" - 0.1") for 16 bright southern Herschel sources at $1.5 < z < 4.2$. With only six and a…

Generating molecular structures with desired properties is a critical task with broad applications in drug discovery and materials design. We propose 3M-Diffusion, a novel multi-modal molecular graph generation method, to generate diverse,…

Machine Learning · Computer Science 2024-10-04 Huaisheng Zhu , Teng Xiao , Vasant G Honavar